Ethernet support

[sy2002]

Quote from @MJoergen in a Skype conversation:

Here's an idea for M2M version 3 (or whatever): Add ethernet support (UDP and/or TCP) in QNICE, and then let it read files from a network file share. For instance, in the OSM one would configure an IP address, and then the file browser would read files from a server instead of from the SDCard. This would require users to setup a file sharing server on their host PC. I actually played around with that some years ago using the TFTP protocol, but perhaps HTTP is more "modern". Anyway, this requires implementing a TCP/IP stack in QNICE assembly. This would be a purely framework-only feature, i.e. the core would be agnostic of it.

At a later stage one could perhaps somehow add support for it in the C64 core, e.g. by assigning device number 9 or 10 to this feature, so users could just type LOAD "$",9,1 to browse the file server directly.

[sy2002]

Would also be helpful for this here:

#41

And for this idea from ROADMAP.md from the C64 core:

Implement a remote-control mechanism via Serial/JTAG (similar to what already works on the MEGA65 core) that allows us to remote-control the C64 core so that we can for example run whole test suites remotely. If possible we should think about implementing this feature on the MiSTer2MEGA65 framework level so that all cores can benefit.

Add the Vice test suite to our repertoire of tests and use the above-mentioned mechanism to execute on it: https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/testbench/